带有用于多行插入的循环的 SQL Server 触发器

Question

我已经为我的数据库创建了触发器来处理一些插入，但是当我在 1 个 SQL 查询中添加多个值时它不起作用:

ALTER TRIGGER [dbo].[ConferenceDayTrigger]
ON [dbo].[Conferences]
AFTER INSERT
AS 
BEGIN
    DECLARE @ID INT
    DECLARE @dayC INT
    DECLARE @counter INT

    SET @counter = 1
    SET @ID = (SELECT  IDConference FROM Inserted)
    SET @dayC = (SELECT   DATEDIFF(DAY, start,finish) FROM Inserted)

    WHILE @counter <= @dayC + 1 
    BEGIN
        EXEC AddConferenceDay @Id, @counter
        SET @counter = @counter +1
    END
END

对于单次插入，它工作正常。但是我应该更改/添加什么以使其对每一行插入的值执行？

Answer 1

如果您无法更改存储过程，那么这可能是(极少数)使用游标的情况之一。双循环，实际上:

ALTER TRIGGER [dbo].[ConferenceDayTrigger]
ON [dbo].[Conferences]
AFTER INSERT
AS 
BEGIN
     DECLARE @ID INT;
     DECLARE @dayC INT;
     DECLARE @counter INT
     SET @counter = 1;

     DECLARE yucky_Cursor CURSOR FOR
        SELECT IDConference, DATEDIFF(DAY, start,finish) FROM Inserted; 
     OPEN yucky_Cursor; /*Open cursor for reading*/


     FETCH NEXT FROM yucky_Cursor INTO @ID, @dayC;
     WHILE @@FETCH_STATUS = 0 
     BEGIN
         WHILE @counter <= @dayC + 1
         BEGIN
             EXEC AddConferenceDay @Id, @counter;
             SET @counter = @counter + 1;
         END;
         FETCH NEXT FROM yucky_Cursor INTO @ID, @dayC;
     END;

    CLOSE yucky_Cursor;
    DEALLOCATE yucky_Cursor;
END;

我怀疑有一种方法可以重构和摆脱游标并使用基于集合的操作。